Temperature sensor and heating cooker

Abstract

A temperature sensor includes a protective tube made of metal, a sensor element including a thermosensitive body and a pair of conductive wires electrically connected to the thermosensitive body and accommodated in the protective tube, a first heat-resistant insulator for ensuring electrical insulation of the pair of conductive wires inside the protective tube, and a second heat-resistant insulator provided between the first heat-resistant insulator and the protective tube for ensuring electrical insulation between the conductive wires and the protective tube.

1 . A temperature sensor, comprising:
 a protective tube made of metal;   a sensor element including a thermosensitive body and a pair of conductive wires electrically connected to the thermosensitive body and accommodated in the protective tube;   a first heat-resistant insulator for ensuring electrical insulation of the pair of conductive wires inside the protective tube; and   a second heat-resistant insulator provided between the first heat-resistant insulator and the protective tube for ensuring electrical insulation between the conductive wires and the protective tube.   
     
     
         2 . The temperature sensor according to  claim 1 , wherein the second heat-resistant insulator comprises a cylindrical ceramic member. 
     
     
         3 . The temperature sensor according to  claim 1 , wherein the second heat-resistant insulator comprises a cylindrical glass member. 
     
     
         4 . The temperature sensor according to  claim 1 , wherein each of the pair of conductive wires is independently inserted through the first heat-resistant insulator. 
     
     
         5 . The temperature sensor according to  claim 1 , wherein only one of the pair of conductive wires is inserted through the first heat-resistant insulator. 
     
     
         6 . The temperature sensor according to  claim 5 , further comprising:
 a pair of cylindrical insulators comprising an electrically insulating material for ensuring electrical insulation between the pair of conductive wires, wherein   the pair of conductive wires is inserted through the first heat-resistant insulator in a first area which is an area on a side of an end portion of the protective tube having the end portion which is closed at a front, and is respectively inserted through the pair of cylindrical insulators in a second area at a rear of the first area.   
     
     
         7 . The temperature sensor according to  claim 6 , wherein the second heat-resistant insulator straddles the cylindrical insulators covering the pair of conductive wires on a rear (B) side. 
     
     
         8 . The temperature sensor according to  claim 7 , wherein the conductive wire is mechanically fixed to the protective tube by crimping through a crimping protective covering in an area of the conductive wire where the cylindrical insulator is provided. 
     
     
         9 . The temperature sensor according to  claim 6 , wherein:
 the protective tube further includes a flange that extends in a direction intersecting a length direction of the protective tube; and   a dimension of the second heat-resistant insulator in the length direction is set equal to or less than a dimension in the length direction from the end portion of the protective tube to a position where the flange is provided.   
     
     
         10 . The temperature sensor according to  claim 9 , wherein:
 the conductive wire is mechanically fixed to the protective tube by crimping through a crimping protective covering in an area of the conductive wire where the cylindrical insulator is provided; and
 the crimping is applied at a rear of the position where the flange of the protective tube is provided. 
   
     
     
         11 . The temperature sensor according to  claim 10 , wherein an outer surface of the protective tube is black. 
     
     
         12 . A heating cooker in which the temperature sensor according to  claim 1  is arranged in a heating chamber.